view test/testjoystick.c @ 3474:1edb86163d62

Of COURSE that trick wouldn't work on all renderers. Fall back to something for now, hopefully figure out a better way to do this later. If we have to, we can use vertical line and horizontal line textures for vertical and horizontal lines, and then create custom textures for diagonal lines and software render those. It's terrible, but at least it would be pixel perfect.
author Sam Lantinga <slouken@libsdl.org>
date Sat, 21 Nov 2009 07:22:59 +0000
parents f55c87ae336b
children
line wrap: on
line source


/* Simple program to test the SDL joystick routines */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "SDL.h"

#ifdef __IPHONEOS__
#define SCREEN_WIDTH	320
#define SCREEN_HEIGHT	480
#else
#define SCREEN_WIDTH	640
#define SCREEN_HEIGHT	480
#endif

void
WatchJoystick(SDL_Joystick * joystick)
{
    SDL_Surface *screen;
    const char *name;
    int i, done;
    SDL_Event event;
    int x, y, draw;
    SDL_Rect axis_area[6][2];

    /* Set a video mode to display joystick axis position */
    screen = SDL_SetVideoMode(SCREEN_WIDTH, SCREEN_HEIGHT, 16, 0);
    if (screen == NULL) {
        fprintf(stderr, "Couldn't set video mode: %s\n", SDL_GetError());
        return;
    }

    /* Print info about the joystick we are watching */
    name = SDL_JoystickName(SDL_JoystickIndex(joystick));
    printf("Watching joystick %d: (%s)\n", SDL_JoystickIndex(joystick),
           name ? name : "Unknown Joystick");
    printf("Joystick has %d axes, %d hats, %d balls, and %d buttons\n",
           SDL_JoystickNumAxes(joystick), SDL_JoystickNumHats(joystick),
           SDL_JoystickNumBalls(joystick), SDL_JoystickNumButtons(joystick));

    /* Initialize drawing rectangles */
    memset(axis_area, 0, (sizeof axis_area));
    draw = 0;

    /* Loop, getting joystick events! */
    done = 0;
    while (!done) {
        while (SDL_PollEvent(&event)) {
            switch (event.type) {
            case SDL_JOYAXISMOTION:
                printf("Joystick %d axis %d value: %d\n",
                       event.jaxis.which,
                       event.jaxis.axis, event.jaxis.value);
                break;
            case SDL_JOYHATMOTION:
                printf("Joystick %d hat %d value:",
                       event.jhat.which, event.jhat.hat);
                if (event.jhat.value == SDL_HAT_CENTERED)
                    printf(" centered");
                if (event.jhat.value & SDL_HAT_UP)
                    printf(" up");
                if (event.jhat.value & SDL_HAT_RIGHT)
                    printf(" right");
                if (event.jhat.value & SDL_HAT_DOWN)
                    printf(" down");
                if (event.jhat.value & SDL_HAT_LEFT)
                    printf(" left");
                printf("\n");
                break;
            case SDL_JOYBALLMOTION:
                printf("Joystick %d ball %d delta: (%d,%d)\n",
                       event.jball.which,
                       event.jball.ball, event.jball.xrel, event.jball.yrel);
                break;
            case SDL_JOYBUTTONDOWN:
                printf("Joystick %d button %d down\n",
                       event.jbutton.which, event.jbutton.button);
                break;
            case SDL_JOYBUTTONUP:
                printf("Joystick %d button %d up\n",
                       event.jbutton.which, event.jbutton.button);
                break;
            case SDL_KEYDOWN:
                if (event.key.keysym.sym != SDLK_ESCAPE) {
                    break;
                }
                /* Fall through to signal quit */
            case SDL_QUIT:
                done = 1;
                break;
            default:
                break;
            }
        }
        /* Update visual joystick state */
        for (i = 0; i < SDL_JoystickNumButtons(joystick); ++i) {
            SDL_Rect area;

            area.x = i * 34;
            area.y = SCREEN_HEIGHT - 34;
            area.w = 32;
            area.h = 32;
            if (SDL_JoystickGetButton(joystick, i) == SDL_PRESSED) {
                SDL_FillRect(screen, &area, 0xFFFF);
            } else {
                SDL_FillRect(screen, &area, 0x0000);
            }
            SDL_UpdateRects(screen, 1, &area);
        }

        for (i = 0;
             i < SDL_JoystickNumAxes(joystick) / 2
             && i < SDL_arraysize(axis_area); ++i) {
            /* Erase previous axes */
            SDL_FillRect(screen, &axis_area[i][draw], 0x0000);

            /* Draw the X/Y axis */
            draw = !draw;
            x = (((int) SDL_JoystickGetAxis(joystick, i * 2 + 0)) + 32768);
            x *= SCREEN_WIDTH;
            x /= 65535;
            if (x < 0) {
                x = 0;
            } else if (x > (SCREEN_WIDTH - 16)) {
                x = SCREEN_WIDTH - 16;
            }
            y = (((int) SDL_JoystickGetAxis(joystick, i * 2 + 1)) + 32768);
            y *= SCREEN_HEIGHT;
            y /= 65535;
            if (y < 0) {
                y = 0;
            } else if (y > (SCREEN_HEIGHT - 16)) {
                y = SCREEN_HEIGHT - 16;
            }

            axis_area[i][draw].x = (Sint16) x;
            axis_area[i][draw].y = (Sint16) y;
            axis_area[i][draw].w = 16;
            axis_area[i][draw].h = 16;
            SDL_FillRect(screen, &axis_area[i][draw], 0xFFFF);

            SDL_UpdateRects(screen, 2, axis_area[i]);
        }
    }
}

int
main(int argc, char *argv[])
{
    const char *name;
    int i;
    SDL_Joystick *joystick;

    /* Initialize SDL (Note: video is required to start event loop) */
    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_JOYSTICK) < 0) {
        fprintf(stderr, "Couldn't initialize SDL: %s\n", SDL_GetError());
        exit(1);
    }

    /* Print information about the joysticks */
    printf("There are %d joysticks attached\n", SDL_NumJoysticks());
    for (i = 0; i < SDL_NumJoysticks(); ++i) {
        name = SDL_JoystickName(i);
        printf("Joystick %d: %s\n", i, name ? name : "Unknown Joystick");
        joystick = SDL_JoystickOpen(i);
        if (joystick == NULL) {
            fprintf(stderr, "SDL_JoystickOpen(%d) failed: %s\n", i,
                    SDL_GetError());
        } else {
            printf("       axes: %d\n", SDL_JoystickNumAxes(joystick));
            printf("      balls: %d\n", SDL_JoystickNumBalls(joystick));
            printf("       hats: %d\n", SDL_JoystickNumHats(joystick));
            printf("    buttons: %d\n", SDL_JoystickNumButtons(joystick));
            SDL_JoystickClose(joystick);
        }
    }

    if (argv[1]) {
        joystick = SDL_JoystickOpen(atoi(argv[1]));
        if (joystick == NULL) {
            printf("Couldn't open joystick %d: %s\n", atoi(argv[1]),
                   SDL_GetError());
        } else {
            WatchJoystick(joystick);
            SDL_JoystickClose(joystick);
        }
    }
    SDL_QuitSubSystem(SDL_INIT_VIDEO | SDL_INIT_JOYSTICK);

    return (0);
}